1. Field of the Invention PA1 i) heating and increasing a temperature of a raw material mixture which has a glass composition containing a salt or an oxide of a flame reaction metal to form an intermediate base material in which the salt of the flame reaction metal or the like has been thermally decomposed and which is in a temporary sintered state or a fused glass state, PA1 ii) grinding the intermediate base material to produce a ground material, PA1 iii) mixing the ground material together with a liquid and, optionally, a binder to form a viscous flame reaction material, PA1 iv) applying the viscous flame reaction material to a substrate, and PA1 v) heating the viscous flame reaction material to a temperature, which is not lower than a vitrification melting temperature of the viscous flame reaction material to fusion bond the flame reaction material to the substrate. PA1 heating and increasing a temperature of a raw material mixture, which has a glass composition containing a salt or an oxide of a flame reaction metal thereby forming an intermediate base material in which the salt or oxide of the flame reaction metal has been thermally decomposed and which is in a temporary sintered state or a fused glass state, and PA1 grinding the intermediate base material. PA1 i) mixing a raw material mixture which has a glass composition containing a salt or an oxide of a flame reaction metal, together with a liquid and, optionally, a binder to form a viscous flame reaction material, PA1 ii) applying the viscous flame reaction material to a substrate, and PA1 iii) heating the viscous flame reaction material to a temperature which is not lower than a vitrification melting temperature of the flame reaction material to fusion bond the flame reaction material to the substrate, PA1 i) mixing a raw material mixture which has a glass composition containing a salt of a flame reaction metal together with a liquid and, optionally, a binder to form a viscous liquid-like flame reaction material, PA1 ii) applying the viscous liquid-like flame reaction material to a substrate, and PA1 iii) heating the viscous liquid-like flame reaction material to a temperature which is not lower than a vitrification melting temperature of the flame reaction material to fusion bond the flame reaction material to the substrate,
This invention relates to a process for producing a flame reaction member for burners, which is to be located in a gas combustion appliance, such as a gas lighter for smoker's requisites, a lighter, or a torch, and which undergoes a flame reaction and colors a gas flame produced by gas combustion with a burner of the gas combustion appliance. This invention also relates to a flame reaction base material for use in the process for producing a flame reaction member for burners.
2. Description of the Prior Art
In combustion appliances, such as candles, lighters, and torches, combustion flames have heretofore been often colored with flame reaction materials. The coloring of combustion flames is effective to enhance the aesthetic and decorative values of the combustion flames. Also, it is effective for safety to impart a color to colorless combustion flames such that they can be identified.
Flame reactions with the flame reaction materials utilize a phenomenon such that, when salts of alkali metals, alkaline earth metals, and the like, are heated heavily in flames generated by burners, colors inherent to the respective metals can be formed in the flames In order to color combustion flames, salts of metal elements capable of forming required flame colors may be interposed in the combustion flames.
For example, in order to color the flames produced by candles, a metal stearate serving as a flame reaction material is mixed into a wax material. During the combustion of the candle, simultaneously with the volatilization of the molten wax material, the flame reaction material is volatilized and is caused to form a color by being heated in the flame.
In order to color the flames produced by other combustion appliances, an aqueous solution of a water-soluble inorganic salt is sprayed into the flame. Alternatively, a carrier is impregnated with an aqueous solution of a water-soluble inorganic salt, dried, and then located at a high temperature portion of the flame. In particular, in the cases of gas lighters, a coiled nichrome wire having been coated with a flame reaction material is located in the vicinity of the fire outlet of the gas lighter, and a colored flame is thereby obtained.
Also, a process for producing a flame reaction member has theretofore been known, wherein a flame reaction material containing a flame reaction agent is adhered to a wire-shaped substrate by dipping, or the like, the substrate, to which the flame reaction material has been adhered, is heated, a binder, or the like, contained in the flame reaction material is thereby removed, and the substrate is baked such that the flame reaction material may be supported on the substrate.
In a gas combustion appliances provided with burners, in which primary air is mixed into a fuel gas, in cases where a flame is to be colored by the utilization of a flame reaction as described above, it is required that a flame reaction member can steadily undergo the flame reaction in order to provide a stable colored flame, has a good heat durability with respect to repeated combustion, and has a long service life. However, with the flame reaction member, which is formed by merely adhering a flame reaction material onto a substrate by baking in the manner described above, such requirements cannot be satisfied sufficiently.
Specifically, a viscous liquid-like flame reaction material may be prepared by mixing a flame reaction agent, which is constituted of a salt of an alkali metal, a salt of an alkaline earth metal, or the like, capable of undergoing a flame reaction, and a binder, or the like. The viscous liquid-like flame reaction material may then be adhered to a loop- or coil-shaped substrate by a coating process or a dipping process. The substrate, to which the flame reaction material has been adhered, may then be baked, and a flame reaction member may thereby be formed. The flame reaction member may be located at a fire outlet of a gas combustion appliance, such as a gas lighter. In such cases, the problems occur in that, if the flame reaction material is chemically unstable, it will deteriorate when being left to stand for a long period of time, and a desired flame reaction cannot be obtained any more. Also, if the heat-resistance strength is low, the flame reaction material will crack due to rapid heating and quenching cycles due to lighting and extinguishment during use, the cracked portions will come off the substrate, and therefore several portions of the flame cannot be colored.
Also, when a flame reaction material colors a flame, the flame reaction metal is evaporated into the flame and exhausted due to heating with the gas flame. Therefore, the problems occur in that, as the flame reaction material is used, the amount of the flame reaction metal evaporated becomes small, and the formed color becomes unstable or pale. Thus the flame reaction material cannot be used repeatedly or for a long time, and its service life is short. Further, depending upon the composition of the flame reaction material, the problems occur in that the activity of the flame reaction is low, and therefore a long time is required from the heating to the color formation. In particular, in the cases of gas lighters, it is necessary that the time required from the lighting to the occurrence of the color formation of the flame with the flame reaction is as short as possible. Furthermore, a good durability with respect to repeated heating and quenching is required.
As described above, as characteristics of the flame reaction material, it is required that the flame reaction material is firmly supported on the substrate, that the flame reaction material is chemically stable and does not deteriorate even when being left to stand for a long period of time in air, and that the flame reaction material undergoes little exhaustion during the repeated use, remains on the substrate continuously to always undergo the flame reaction, and thus has a long service life.
Accordingly, in order to satisfy the requirements described above, several processes for producing a flame reaction member for burners have been proposed in, for example, U.S. Pat. No. 5,743,724 and Japanese Unexamined Patent Publication No. 8(1996)-296849. In the proposed processes, an oxide or a salt of a metal capable of undergoing a flame reaction is employed as a flame reaction agent. A mixture of the flame reaction agent and an appropriate amount of a metal oxide, which is capable of being mixed and fused together with the flame reaction agent and vitrified without adversely affecting the desired flame reaction, is adhered to a substrate by baking. Alternatively, in order for the flame reaction agent to be firmly fixed to the substrate, a low-melting-temperature glass material is added to the aforesaid mixture of the flame reaction agent and the metal oxide, which is capable of being mixed and fused together with the flame reaction agent, and the resulting mixture is adhered to the substrate by baking. In this manner, a flame reaction member for burners is produced.
However, in cases where a vitreous flame reaction material is to be fusion bonded to the substrate, if an oxide of a flame reaction metal is employed as a flame reaction agent in the flame reaction material, no problems will particularly occur. However, if a salt, such as a carbonate, a sulfate, or a nitrate, of a flame reaction metal is employed, fusion bonding of the flame reaction material to the substrate cannot be carried out sufficiently. As a result, the problems occur in that the amount of the flame reaction material carried on the substrate becomes insufficient, and color forming characteristics and durability cannot be kept good.
Specifically, a vitreous flame reaction material, which contains a flame reaction constituent, may be mixed with a liquid, such as water, and a binder, when necessary, and a viscous liquid may thereby be prepared. The thus prepared viscous liquid may then be supported on a substrate, heated, and baked. In such cases, a certain kind of salt of the flame reaction metal described above is converted into the oxide of the flame reaction metal due to thermal decomposition, and the resulting oxide of the flame reaction metal is fused and vitrified together with the other metal oxides. A different kind of salt of the flame reaction metal, which has a thermal decomposition temperature higher than the vitrification melting temperature, is fused and mixed in the vitrified melt of the other constituents. Also, the liquid, such as water, and the binder, such as a sizing agent, which were added in order to prepare the viscous liquid containing the powdered flame reaction material such that the viscous liquid may be supported on the substrate by coating or dipping, are evaporated and burned off due to the heating for fusion bonding. Thereafter, the powdered flame reaction material is fixed with a weak fixing force to the substrate. When the flame reaction material is heated to a temperature higher than the melting temperature, fused and vitrified, the flame reaction material is firmly fixed to the substrate. However, during the temperature increasing step prior to the fusion and vitrification, if gases are produced quickly due to the thermal decomposition of the salts of the flame reaction metal and other compounds, foaming occurs in the flame reaction material, which is being bonded weakly to the substrate prior to the fusion and vitrification, due to the generation of the thermal decomposition gases. As a result, the flame reaction material becomes cracked and scattered, and the carrying of the flame reaction material on the substrate cannot be carried out appropriately.